Genome-wide characterization of the bHLH gene family in Gynostemma pentaphyllum reveals its potential role in the regulation of gypenoside biosynthesis.

BACKGROUND: Gynostemma pentaphyllum, an ancient Chinese herbal medicine, serves as a natural source of gypenosides with significant medicinal properties. Basic helix-loop-helix (bHLH) transcription factors play pivotal roles in numerous biological processes, especially in the regulation of secondary metabolism in plants. However, the characteristics and functions of the bHLH genes in G. pentaphyllum remain unexplored, and their regulatory role in gypenoside biosynthesis remains poorly elucidated. RESULTS: This study identified a total of 111 bHLH members in G. pentaphyllum (GpbHLHs), categorizing them into 26 subgroups based on shared conserved motif compositions and gene structures. Collinearity analysis illustrated that segmental duplications predominately lead to the evolution of GpbHLHs, with most duplicated GpbHLH gene pairs undergoing purifying selection. Among the nine gypenoside-related GpbHLH genes, two GpbHLHs (GpbHLH15 and GpbHLH58) were selected for further investigation based on co-expression analysis and functional prediction. The expression of these two selected GpbHLHs was dramatically induced by methyl jasmonate, and their nuclear localization was confirmed. Furthermore, yeast one-hybrid and dual-luciferase assays demonstrated that GpbHLH15 and GpbHLH58 could bind to the promoters of the gypenoside biosynthesis pathway genes, such as GpFPS1, GpSS1, and GpOSC1, and activate their promoter activity to varying degrees. CONCLUSIONS: In conclusion, our findings provide a detailed analysis of the bHLH family and valuable insights into the potential use of GpbHLHs to enhance the accumulation of gypenosides in G. pentaphyllum.

Integrated transcriptomics and metabolomics analysis provides insights into aromatic volatiles formation in Cinnamomum cassia bark at different harvesting times.

BACKGROUND: Cinnamomum cassia Presl, classified in the Lauraceae family, is widely used as a spice, but also in medicine, cosmetics, and food. Aroma is an important factor affecting the medicinal and flavoring properties of C. cassia, and is mainly determined by volatile organic compounds (VOCs); however, little is known about the composition of aromatic VOCs in C. cassia and their potential molecular regulatory mechanisms. Here, integrated transcriptomic and volatile metabolomic analyses were employed to provide insights into the formation regularity of aromatic VOCs in C. cassia bark at five different harvesting times. RESULTS: The bark thickness and volatile oil content were significantly increased along with the development of the bark. A total of 724 differentially accumulated volatiles (DAVs) were identified in the bark samples, most of which were terpenoids. Venn analysis of the top 100 VOCs in each period showed that twenty-eight aromatic VOCs were significantly accumulated in different harvesting times. The most abundant VOC, cinnamaldehyde, peaked at 120 months after planting (MAP) and dominated the aroma qualities. Five terpenoids, α-copaene, ß-bourbonene, α-cubebene, α-funebrene, and δ-cadinene, that peaked at 240 MAP could also be important in creating C. cassia's characteristic aroma. A list of 43,412 differentially expressed genes (DEGs) involved in the biosynthetic pathways of aromatic VOCs were identified, including phenylpropanoids, mevalonic acid (MVA) and methylerythritol phosphate (MEP). A gene-metabolite regulatory network for terpenoid and phenylpropanoid metabolism was constructed to show the key candidate structural genes and transcription factors involved in the biosynthesis of terpenoids and phenylpropanoids. CONCLUSIONS: The results of our research revealed the composition and changes of aromatic VOCs in C. cassia bark at different harvesting stages, differentiated the characteristic aroma components of cinnamon, and illuminated the molecular mechanism of aroma formation. These foundational results will provide technical guidance for the quality breeding of C. cassia.

Atom-based optical polarization modulator.

In this work, we employ 87Rb atoms as rotation media to manipulate the polarization of optical fields in both magnetic and magnetic-free environments. Employing the nonlinear magneto-optical rotation mechanism, we achieve a state-of-the-art magneto-optical rotation coefficient of 1.74×108 rad⋅T-1⋅m-1 which is four orders of magnitude higher than commonly employed materials. Additionally, in a magnetic-free environment, we achieve all-optical cross-polarization modulation between the pump and probe light via Rb atoms. The nonlinear magneto-optical rotation configuration introduces inventive techniques for a new type of magneto-optical modulator while the all-optical configuration paves the way for exploring photonic integrated circuit (PIC) devices free from disruptions caused by electrical or magnetic crosstalk.

KF-catalyzed direct thiomethylation of carboxylic acids with DMSO to access methyl thioesters.

With dimethyl sulfoxide (DMSO) as the methylthio source, a KF-catalyzed strategy was employed for the direct thiomethylation of carboxylic acids with DMSO for the preparation of methyl thioesters. In this process, a wide range of methyl thioesters were obtained in moderate to excellent yields. This novel strategy features the first use of DMSO as a methylthiolating agent for the construction of methyl thioesters, transition metal-free conditions, inexpensive reagents, easy workup, broad substrate scope and sustainability. Additionally, this procedure can be readily scaled up to a gram scale.

Seed germination and seedling growth response of Leymus chinensis to the allelopathic influence of grassland plants.

Allelopathy has a profound impact on the germination and growth of plants, influencing the establishment of plant populations and shaping community ecological patterns. However, the allelopathic potential of many grassland species remains poorly understood. In this study, we prepared aqueous extracts from 17 herbaceous plants to investigate their allelopathic effects on the seed germination and seedling growth of Leymus chinensis, a dominant grassland species. Our results revealed that the response of L. chinensis to allelopathic compounds was dependent on the specific plant species, extract concentration, and target plant organ. Notably, Fabaceae plants exhibited a stronger allelopathic potential than Poaceae, Asteraceae, and other plant families. Moreover, we observed that root growth of L. chinensis was more sensitive to allelopathy than shoot growth, and seed germination was more affected than seedling growth. Generally, the germination of L. chinensis was strongly inhibited as the donor plant extract concentration increased. The leachate of Fabaceae plants inhibited the seedling growth of L. chinensis at concentrations ranging from 0.025 to 0.1 g mL-1. On the other hand, the leachate from other families' plants exhibited either inhibitory or hormetic effects on the early growth of L. chinensis, promoting growth at 0.025 g mL-1 and hindering it at concentrations between 0.05 and 0.1 g mL-1. These findings highlight the significant allelopathic potential of grassland plants, which plays a critical role in establishing plant populations and associated ecological processes. In addition, they shed light on the coexistence of other plants with dominant plants in the community.

MicroRNA-196a-5p facilitates the onset and progression via targeting ITM2B in esophageal squamous cell carcinoma.

Esophageal squamous cell carcinoma (ESCC) is a prevalent malignancy affecting the digestive tract, with an increasing incidence rate worldwide. Recently, numerous studies revealed that microRNAs were associated with gene expression regulation, particularly their involvement in the regulation of tumor cells, garnering widespread attention. Here, we discovered that miR-196a-5p was significantly upregulated in both ESCC tissues and cells, which was correlated with an unfavorable prognosis. Series functional in vitro investigations have confirmed that silencing miR-196a-5p obviously restrained the ESCC cells malignant phenotypes and promoted apoptosis. Bioinformatics analysis and rescue experiments revealed that miR-196a-5p directly targeted ITM2B, exerting influence on the development of ESCC cells through negative regulation of ITM2B expression. Xenograft mouse models were established for conducting in vivo experiments, providing further confirmation of the regulatory mechanism and biological significance of the miR-196a-5p/ITM2B axis in ESCC. Our research demonstrated miR-196a-5p promoted ESCC malignant progression by interacting with ITM2B, thereby providing novel clues and potential targets for the new diagnosis and thereby of ESCC.

Hybrid Integration of GaP Photonic Crystal Cavities with Silicon-Vacancy Centers in Diamond by Stamp-Transfer.

Optically addressable solid-state defects are emerging as some of the most promising qubit platforms for quantum networks. Maximizing photon-defect interaction by nanophotonic cavity coupling is key to network efficiency. We demonstrate fabrication of gallium phosphide 1-D photonic crystal waveguide cavities on a silicon oxide carrier and subsequent integration with implanted silicon-vacancy (SiV) centers in diamond using a stamp-transfer technique. The stamping process avoids diamond etching and allows fine-tuning of the cavities prior to integration. After transfer to diamond, we measure cavity quality factors (Q) of up to 8900 and perform resonant excitation of single SiV centers coupled to these cavities. For a cavity with a Q of 4100, we observe a 3-fold lifetime reduction on-resonance, corresponding to a maximum potential cooperativity of C = 2. These results indicate promise for high photon-defect interaction in a platform which avoids fabrication of the quantum defect host crystal.

Team interaction behaviors correlates with team creativity among nursing students: Canonical correlation and moderation analyses.

BACKGROUND: Prior studies have indicated team members' interaction behaviors may predict creativity among nursing students. METHODS: This study investigated the correlation between interaction behaviors and creativity, both individual- and team-level, among nursing students. In this cross-sectional quantitative study, data were obtained from self-reported questionnaires. Individual creativity was assessed using the Torrance Tests of Creative Thinking scale; the perceived team interaction behavior and team creativity were assessed using validated instruments. Canonical correlation analysis was conducted to determine the overall correlation between interaction behaviors, and creativity, and the moderating effect of female proportion dominance was also examined. RESULTS: A total of 164 nursing students (84.1% female) arranged into 14 teams were included in this study. Canonical correlation analysis showed a positive correlation between interaction behaviors and creativity (correlation = 0.88). All dimensions of interactive behaviors were positively related to creativity dimensions. A stronger correlation to team creativity (correlation = 1) was found compared to individual creativity (correlation = 0.07). This study demonstrated that individual interactive behaviors including spontaneous communication and helping behavior predicted high team creativity. CONCLUSIONS: This insight may be valuable for nursing education programs seeking to foster creativity and effective teamwork. The potential moderating effect of female proportions on team interaction behaviors and creativity should be investigated further.

A transcriptional cascade involving BBX22 and HY5 finely regulates both plant height and fruit pigmentation in citrus.

Dwarfing is a pivotal agronomic trait affecting both yield and quality. Citrus species exhibit substantial variation in plant height, among which internode length is a core element. However, the molecular mechanism governing internode elongation remains unclear. Here, we unveiled that the transcriptional cascade consisting of B-BOX DOMAIN PROTEIN 22 (BBX22) and ELONGATED HYPOCOTYL 5 (HY5) finely tunes plant height and internode elongation in citrus. Loss-of-function mutations of BBX22 in an early-flowering citrus (Citrus hindsii "SJG") promoted internode elongation and reduced pigment accumulation, whereas ectopic expression of BBX22 in SJG, sweet orange (C. sinensis), pomelo (C. maxima) or heterologous expression of BBX22 in tomato (Solanum lycopersicum) significantly decreased internode length. Furthermore, exogenous application of gibberellin A3 (GA3) rescued the shortened internode and dwarf phenotype caused by BBX22 overexpression. Additional experiments revealed that BBX22 played a dual role in regulation internode elongation and pigmentation in citrus. On the one hand, it directly bound to and activated the expression of HY5, GA metabolism gene (GA2 OXIDASE 8, GA2ox8), carotenoid biosynthesis gene (PHYTOENE SYNTHASE 1, PSY1) and anthocyanin regulatory gene (Ruby1, a MYB DOMAIN PROTEIN). On the other hand, it acted as a cofactor of HY5, enhancing the ability of HY5 to regulate target genes expression. Together, our results reveal the critical role of the transcriptional cascade consisting of BBX22 and HY5 in controlling internode elongation and pigment accumulation in citrus. Unraveling the crosstalk regulatory mechanism between internode elongation and fruit pigmentation provides key genes for breeding of novel types with both dwarf and health-beneficial fortification in citrus.

Evaluation of combined epiretinal membrane removal with intravitreal triamcinolone injection utilizing ectopic inner foveal layer staging scheme.

OBJECTIVE: To investigate the macular morphological and visual outcomes of combined idiopathic epiretinal membrane (iERM) removal with triamcinolone acetonide (TA) injection based on consideration of the ectopic inner foveal layer (EIFL) staging scheme. METHODS: Retrospective case-control study. The clinical data of 84 eyes of 84 patients who underwent vitrectomy for iERM between 2018 and 2022 were reviewed. The enrolled subjects were divided into the TA and non-TA groups. Fifty-one eyes received intravitreal TA injection following vitrectomy and ERM peeling (TA group), and 33 were only treated by standard vitrectomy and ERM peeling (non-TA group). Preoperative and postoperative EIFL stages, central foveal thickness (CFT), and best-corrected visual acuity (BCVA) were compared between both groups. RESULTS: After a mean follow-up of 7.69 ± 3.68 months, both groups exhibited significant improvement in EIFL stages (P < 0.01), with no discernible advantage observed in the TA group. The TA and non-TA groups demonstrated improvement in the EIFL stages in 56.86 and 63.64% of eyes, respectively (P = 0.43). The CFT and BCVA significantly improved in both groups at the final visit (P < 0.01). However, CFT in the non-TA group displayed a more significant reduction during the follow-up (P < 0.03). Subgroup analysis revealed no significant differences in postoperative CFT and BCVA between the two groups in cases with or without continuous EIFL (P > 0.10). CONCLUSION: Our findings indicate that combined intravitreal TA injection following ERM removal conferred no significant benefits in alleviating macular thickening or improving visual acuity in iERM.

Heterocyclic Boron Acid Catalyzed Dehydrative Amidation of Aliphatic/Aromatic Carboxylic Acids with Amines.

A commercially available and versatile dehydrative amidation catalyst, featuring a thianthrene boron acid structure, has been developed. The catalyst shows high catalytic activity to both aliphatic and less reactive aromatic carboxylic acid substrates, including several bioactive or clinical molecules with a carboxylic acid group.

The Effects of Animation on the Guessability of Universal Healthcare Symbols for Middle-Aged and Older Adults.

OBJECTIVE: The purpose of this study was to investigate whether animation can help to improve the comprehension of universal healthcare symbols for middle-aged and older adults. BACKGROUND: The Hablamos Juntos (HJ) healthcare symbol system is a set of widely used universal healthcare symbols that were developed in the United States. Some studies indicated that HJ healthcare symbols are not well-understood by users in non-English-speaking areas. Other studies found that animations can improve users' comprehension of complex symbols. Thus, we wanted to test whether animation could help to improve users' comprehension of HJ symbols. METHODS: The participants included 40 middle-aged and 40 older adults in Taiwan. We redesigned the 12 HJ symbols into three visual formats-static, basic animation, and detailed animation-and compared them to find which best improved the participants' guessability scores. RESULTS: (1) Middle-aged adults' comprehension of static and basic animated symbols was significantly better than that of older adults, but there was no significant difference in the guessability scores between the two age groups in terms of detailed animated symbols; (2) In general, both basic animation and detailed animation significantly improved the guessability score, but the effect with detailed animation was significantly greater than that with basic animation; (3) Older women were more receptive to detailed animation and showed better guessing performance. CONCLUSION: Detailed animation contains more details and provides a more complete explanation of the concept of the static symbols, helping to improve the comprehension of HJ symbols for middle-aged and older adult users. APPLICATION: Our findings provide a reference for the possibility of new style symbol design in the digital and aging era, which can be applied to improve symbol comprehension.

[Identification of terpene synthase gene family in Gynostemma pentaphyllum and expression pattern analysis under abiotic stresses].

The present study aimed to investigate the composition of the terpene synthase(TPS) gene family in Gynostemma pentaphyllum and its role in abiotic stresses. The G. pentaphyllum TPS gene family was identified and analyzed at the genome-wide level using bioinformatics analysis, and the expression patterns of these family members were analyzed in different tissues of G. pentaphyllum as well as under various abiotic stresses. The results showed that there were 24 TPS gene family members in G. pentaphyllum with protein lengths ranging from 294 to 842 aa. All of them were localized in the cytoplasm or chloroplasts and unevenly distributed on the 11 chromosomes of G. pentaphyllum. The results of the phylogenetic tree showed that the G. pentaphyllum TPS gene family members could be divided into five subfamilies. As revealed by the analysis of promoter cis-acting elements, TPS gene family members in G. pentaphyllum were predicted to respond to a variety of abiotic stresses such as salt, low temperature, and dark stress. The analysis of gene expression patterns in different tissues of G. pentaphyllum revealed that nine TPS genes were tissue-specific in expression. The qPCR results showed that GpTPS16, GpTPS17, and GpTPS21 responded to a variety of abiotic stresses. This study is expected to provide references in guiding the further exploration of the biological functions of G. pentaphyllum TPS genes under abiotic stresses.

Demonstration of a bi-directionally tunable arrayed waveguide grating with ultra-low thermal power using S-shaped architecture and parallel-circuit configuration.

A thermally bi-directionally tunable arrayed waveguide grating (TBDTAWG) is proposed and demonstrated on a silicon-on-insulator (SOI) platform. The device is composed of passive and active designs for realizations of an AWG and fine tuning of its filtering responses. Given that the required length difference between adjacent arrayed waveguides for the SOI platform is considerably short (∼3-5 µm) due to a high index contrast, an S-shaped architecture with a larger footprint instead of a rectangular one is employed in the AWG. Bi-directionally tunable functions, i.e., both red- and blue-shift tunable functions, can be achieved by using two triangular thermal-tuning regions with complementary phase distributions in the S-shaped architecture despite using only materials with positive thermo-optic coefficients, i.e., Si and SiO2. Measurement results illustrate that both red- or blue-shifted spectra can be achieved and a linear bi-directional shift-to-power ratio of ±30.5 nm/W as well as a wide tuning range of 8 nm can be obtained under an electrical voltage range of 0-2.5 V, showing an agreement between the measurement results and two-dimensional simulation results. This also shows the potential of the proposed TBDTAWG for automatically stabilizing the spectral responses of AWG-based (de)multiplexers for coarse or dense wavelength division multiplexing communication systems by using a feedback control circuit.

TRIPTYCHON-LIKE regulates aspects of both fruit flavor and color in citrus.

Deciphering the genetic basis of organoleptic traits is critical for improving the quality of fruits, which greatly shapes their appeal to consumers. Here, we characterize the citrus R3-MYB transcription factor TRIPTYCHON-LIKE (CitTRL), which is closely associated with the levels of citric acid, proanthocyanidins (PAs), and anthocyanins. Overexpression of CitTRL lowered acidity levels and PA contents in citrus calli as well as anthocyanin and PA contents in Arabidopsis leaves and seeds. CitTRL interacts with the two basic helix-loop-helix (bHLH) proteins CitbHLH1 and ANTHOCYANIN 1 (CitAN1) to regulate fruit quality. We show that CitTRL competes with the R2R3-MYB CitRuby1 for binding to CitbHLH1 or CitAN1, thereby repressing their activation of anthocyanin structural genes. CitTRL also competes with a second R2R3-MYB, CitPH4, for binding to CitAN1, thus altering the expression of the vacuolar proton-pump gene PH5 and Leucoanthocyanidin reductase, responsible for vacuolar acidification and proanthocyanidins biosynthesis, respectively. Moreover, CitPH4 activates CitTRL transcription, thus forming an activator-repressor loop to prevent the overaccumulation of citric acid and PAs. Overall, this study demonstrates that CitTRL acts as a repressor of the accumulation of citric acid, PAs, and anthocyanins by a cross-regulation mechanism. Our results provide an opportunity to simultaneously manipulate these key traits as a means to produce citrus fruits that are both visually and organoleptically appealing.

Reconfigurable scan lens based on an actively controlled optical phased array.

Integrated photonics provides a path for miniaturization of an optical system to a compact chip scale and offers reconfigurability by the integration of active components. Here we report a chip-scale reconfigurable scan lens based on an optical phased array, consisting of 30 actively controlled elements on the InP integrated photonic platform. By configuring the phase shifters, we show scanning of a nearly diffraction-limited focused spot with a full width at half maximum spot size down to 2.7 µm at the wavelength of 1550 nm. We demonstrate the key functions needed for a laser-scanning microscope, including light focusing, collection, and steering. We also perform confocal measurements to detect reflection at selective depths.

Design and synthesis of TPP+-Mitomycin C conjugate with reduced toxicity.

Mitomycin C (MMC) is a class of alkylating anticancer drug, which non-specifically interacts with nuclear DNA and cross-links guanine and cytosine of DNA, thereby affecting DNA replication and synthesis. However, toxic effects largely impeded MMC's clinical applications. In this study, triphenylphosphine groups (TPP+) were attached to MMC via the active aziridine amine with the aim to reduce its toxicity. MTT assay suggested that 5 possessed a good anticancer activity (IC50 = 1.09 µM, A549) with negligible effects on human normal cells (IC50 > 20 µM, L02 and HUVEC), while MMC exhibited IC50 values of less than 2.5 µM on the tested human normal cells. Dose range-finding experiments suggested that 5 had little effect on the body weight and tissues in mouse at a dose of 20 mg/kg, indicating significantly reduced toxicity as compared to MMC (LD50 < 2.5 mg/kg). Collectively, these data suggested that TPP+ group could be an effective vector to reduce toxicity of MMC.

Effect of artificial intelligence-aided colonoscopy for adenoma and polyp detection: a meta-analysis of randomized clinical trials.

BACKGROUND: This meta-analysis aimed to determine whether artificial intelligence (AI) improves colonoscopy outcome metrics i.e. adenoma detection rate (ADR) and polyp detection rate (PDR). METHODS: Two authors independently searched Web of Science, PubMed, Science Direct, and Cochrane Library to find all published research before July 2021 that has compared AI-aided colonoscopy with routine colonoscopy (RC) for detection of adenoma and polyp. RESULTS: This meta-analysis included 10 RCTs with 6629 individuals in AI-aided (n = 3300) and routine (n = 3329) groups. The results showed that both ADR (RR, 1.43; P < 0.001) and PDR (RR, 1.44; P < 0.001) using AI-aided endoscopy were significantly greater when compared with RC. The adenomas detected per colonoscopy (APC) (WMD, 0.25; P = 0.009), polyps detected per colonoscopy (PPC) (WMD, 0.52; P < 0.001), and sessile serrated lesions detected per colonoscopy (SSLPC) (RR, 1.53; P < 0.001) were significantly higher in the AI-aided group compared with the RC group. Subgroup analysis based on size, location, and shape of adenomas and polyps demonstrated that, except for in the cecum and pedunculated adenomas or polyps, the AI-aided groups of the other subgroups are more advantageous. Withdrawal time was longer in the AI-aided group when biopsies were included, while withdrawal time excluding biopsy time showed no significant difference. CONCLUSIONS: AI-aided polyp detection system significantly increases lesion detection rate. In addition, lesion detection by AI is hardly affected by factors such as size, location, and shape.

Adjunctive azithromycin prophylaxis protects women from uterine cesarean scar defect: A randomized controlled trial.

INTRODUCTION: Cesarean scar defect (CSD) is a long-term outcome of cesarean section (CS) and associated with numerous gynecological and obstetric problems. Previous studies indicate that infection may be a risk factor for CSD. Adjunctive azithromycin was shown to reduce the risk of postoperative infection in patients undergoing non-elective primary cesarean delivery in labor or after the rupture of membranes compared with standard antibiotic prophylaxis. This study investigated the protective effect of adjunctive azithromycin in combination with single-dose cephalosporin against CSD in women undergoing non-elective cesarean delivery. MATERIAL AND METHODS: A randomized, double-blind, controlled clinical trial was conducted in a University hospital in Shanghai, China. A total of 242 women who underwent their first non-elective CS were randomly assigned to receive 1500 mg cefuroxime sodium plus 500 mg intravenous azithromycin (n = 121; experimental group) or 1500 mg cefuroxime sodium plus a placebo (n = 121; placebo group). The primary outcome was CSD prevalence, as determined by transvaginal ultrasound and saline infusion sonohysterography within 6 months of delivery. Secondary outcomes were changes in infectious indicators (eg hypersensitive C-reactive protein and procalcitonin), postoperative morbidity, and use of postoperative antibiotics. We also examined the operative procedure, pathogenic microorganism cultures, and fetal outcomes. Outcomes were compared between groups with the chi-squared test, Fisher's exact test, or Student's t test. RESULTS: Between May 2018 and May 2021, 121 women were randomized to each arm. Because the sonographic follow up was disrupted by the coronavirus disease 2019 pandemic and strict management policies, we merged the follow-up time points (6 weeks and 6 months) into a single time period (6 weeks to 6 months); 104 and 108 women in the experimental and placebo groups, respectively, completed the first sonographic follow up. CSD was diagnosed by sonography in 34/104 (32.7%) and 50/108 (46.3%) patients in the experimental and placebo groups, respectively (relative risk 0.71, 95% confidence interval 0.50-0.99; p = 0.043). Characteristics of CSD and short-term infection outcomes did not differ between groups. CONCLUSIONS: A single dose of intravenous 500 mg azithromycin adjunctive to single-dose cefuroxime prophylaxis significantly reduced the incidence of CSD in women undergoing non-elective CS.

Broadband ultra-compact polarization splitter-rotator using diagonally overlapped bi-layer architecture.

A broadband and ultra-compact polarization splitter-rotator based on diagonally overlapped bi-layer architecture and an asymmetrical directional coupler is proposed on a silicon-on-insulator platform. By leveraging the structure over supermode theory, a 1-dB bandwidth of 220 nm, extinction ratio (ER) of <19dB, and cross talk (XT) of <-15.85dB within the span of 1400-1700 nm and coupling length of 4.62 µm are achieved. In addition, TM0-TE0 conversion loss of ∼0.19dB, ER of 35.88 dB, and XT of -30.46dB can be obtained at 1550 nm. The fabrication tolerances are also analyzed, indicating that the insertion losses remain below 1 dB over 1460-1620 nm in terms of width errors and layer-to-layer misalignments within ±10nm. The results show that the proposed device is very suitable to utilize between fibers and for polarization diversity of on-chip systems for broadband operation as well as ultra-compact integration.